The Saproxylic Database

The Wood decomposer database has a history that started as a personal database on beetles (Coleoptera) in the early 1990s. Since then it has developed through three distinct phases to what it has become today.

The saproxylic beetle database (1992-2002)

In his PhD study, Jogeir Stokland worked on documenting the species diversity patterns of wood-inhabiting species in boreal forests in SE Norway. He used free-hanging window traps, which is an efficient method to collect a large number of saproxylic (wood-inhabiting) beetles. A drawback of the method is that one also gets a lot of non-saproxylic species in the traps. Thus, Stokland made a provisional list of about 1100 saproxylic beetle species from Norway and Sweden in the early 1990s to sort his trapping material into saproxylic and non-saproxylic species as well as different substrate preference groups. The list contained classified information about obligate-facultative dependency of dead wood, host tree preference, diameter preference and decay preference based on information extracted from different literature sources.

The reliability of the list was greatly enhanced through a close cooperation with Bengt Ehnström, Sweden – a true expert on the ecology of saproxylic species. Ehnström went through the list in two rounds and made additions, deletions and frequently detailed comments about the species. Thus, the database has developed through cooperation from the very beginning. The file was available to other researchers who needed to sort beetle species into ecological groups.

Excel was the software platform of this database. All information was compiled into a single Excel sheet with separate columns for different wood substrate categories and one column summing up the information sources.

The Nordic saproxylic database (2002-2007)

In 2002, the Swedish board of forestry asked the Swedish Species Information Centre (Artdatabanken) to compile available information about all wood-inhabiting species in Sweden and their preferences for alternative dead wood qualities. The mycologist Anders Dahlberg was project leader and soon he contacted Jogeir Stokland who joined the project. Together with another mycologist, Karl-Henrik Larsson they first made a revised list of different wood qualities. Stokland transferred all information from his beetle database to this project, and also species data for a large number of fungi from his post-doc project. Dahlberg contacted several experts on different organism groups in Sweden and received primary data as well as expert opinions about substrate preferences for a large number of species. Dahlberg also extracted information from several publications with ecological information about saproxylic species (both fungi and insects). The result of the project was a content rich database with information about substrate preferences for about 3600 species, mostly Ascomycetes, Basidiomycetes and Coleoptera, but also Hemiptera, mosses, lichens and vertebrates (bats and birds). Stokland developed the database structure and made scripts to produce overview statistics and output reports from the database. In 2004, a Swedish-language report with English summary presented the main patterns in substrate preferences for each organism groups, see http://www.svo.se/forlag/rapporter/1733.pdf.

By the end of this Swedish project, Dahlberg and Stokland thought that also information and expertise from other Nordic countries should be included in this database since the countries share a large common species pool. Thus, they arranged a workshop at Ekenäs, Sweden in February 2004 and invited 30 experts on saproxylic organisms from Denmark, Finland, Norway and Sweden to see if there was interest to develop a shared Nordic database. The participants were positive to the idea and almost all participants agreed to establish a Nordic saproxylic network and different database working groups with the purpose of enhance the information content for corresponding organism groups (see the Saproxylic network flip).

The next year, the definitions of the wood attributes were revised once more based on input from this broad expert panel. Thus, the classification of dead wood qualities had now reached a mature and stable state that the Nordic experts agreed on. This was an important achievement sine agreement about classification is an essential basis for cooperation. Furthermore, the database consistency strongly depends upon a stable definition of wood attributes.

In 2005-2007, the Nordic saproxylic network succeeded to rise funding to cover expenses of meetings and salary for people who devoted substantial time to digitize information into the database (see the Funding sources flip). In these years the main emphasis was on updating the database for Diptera, Hymenoptera and mites – three species rich organism groups that were superficially covered in the Swedish project. The corresponding working groups held meetings and made coordinated efforts to update the database.

Excel was still the software platform for this Nordic saproxylic database. In addition to the species-wood association table (that had been the core of the database from the beginning), the database evolved to contain a species interaction table to capture associations like fungus-fungivore, host-parasite, prey-predator, etc. Furthermore, an Endnote reference library was established to keep track of all information sources. These three tables were linked together with Delphi scripts that made various output reports. Another development was to scan the original publications as pdf-files to facilitate easier access to the information sources for the working group participants. In order to avoid the impression of a personal database, all data files and pdf-files were uploaded to a common ftp-server in 2005 so that every working group participant could access all data.

The Wood decomposer database (2007-  )

Even if all information in the database was fully accessible to all working group participants through the ftp-server, this technical solution was far from satisfactory. Thus, we decided to transfer the data content to a completely new platform with the specific purpose to make the content Internet-accessible. In 2006 we chose to use a software platform developed by the biologist and software engineer Evgeniy Meyke from Finland.

The Nordic Saproxylic network specified several data structures and functions that this platform needed to provide. All definitions of the wood attribute and the species interaction fields remained unchanged (and thus the data kept their original validity) during this platform change. But the internal data structure changed completely in order to facilitate new database functionality in the Internet version. This internal re-arrangement of the data into the new structure was a rather time-consuming (but worthwhile) process.

As the database entered a fully fledged Internet version accessible in public domain, it was a natural point to re-assess the name of the “Nordic saproxylic database”. It is proposed to call it the “Wood decomposer database”. It is quite evident that several experts outside the Nordic countries wish to use this database (explicit interest has been expressed from Baltic States, Great Britain and several South European countries). Another consideration is that the term saproxylic is rather alien to mycologists, although it is well-established and widely used among entomologists. Still another consideration is that the word saproxylic means absolutely nothing to people outside the circle of devoted experts. Thus, in order to approach both a wider public and potential new sponsors, it is better to use a name that immediately creates a rather good sensation of what this database contains.

Further development

During autumn 2007 the saproxylic network will discuss further developments of the database, including:
- Information content: deepening species documentation
- Information content: widening geographical scope
- Functionality: database views and reports
- Functionality: observation reporting, network maintenance, …
- Functionality: forest management decision support system